Vertical Sounding by Central Induction Method

Abstract

The apparent resistivity methods are widely used to determine the structure of horizontally stratified earth. But with these methods, some material difficulties are unavoided in cases where there are four or more layers. On the other hand, the central induction methods which have been studied by Koenigsberger, Nunier and Stefanescu seem to have a distinct advantage over the resistivity methods in resolving structures involving four or more layers. In this paper the authors discuss the theory of C. I. M. The numerical tables for interpreting the C. I. M. data are presented, and a new procedure in which the phase angle of the resultant magnetic field is measured is proposed.